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User's Guide ______________________________________________________________________
224 _________________________________________________________________ M210667EN-C
6.
Turn on the AC power switch (and also the battery backup switch,
if installed).
CAUTION
When the PWD forward scatter sensor is replaced, the spare unit must
be prepared for LT31 communication using the
Spare Unit
Init
function on the PWD sensor menu. For details, see section Spare Unit
Init on page 244.
7.
Close the interface unit and mount the upper interface unit cover.
Replacing optional LM21 Sensor
The LM21 background luminance sensor is optionally mounted to the
LM21 support arm at the LT31 receiver unit.
To replace the LM21 sensor, the AC power has to be switched off first.
1.
Remove the upper interface unit enclosure and open the interface
unit of the LT31 receiver unit with the provided key.
NOTE
Switch the AC switch to off before proceeding with the next steps. In
case of the optional LTBB111, switch the battery backup switch to off
as well. See Figure 40 on page 83.
2.
Disconnect the LM21 cable plug.
3.
Loosen the LM21 attachment screws and remove the faulty LM21
sensor.
4.
Install the LM21 spare unit using the attachment screws and
washers.
5.
Connect the cable plug to LM21. Make sure that the plug is
carefully and completely screwed on the LM21 receptacle.
6.
Turn on the AC power switch (and also the battery backup switch,
if installed).
7.
Close the interface unit and mount the upper interface unit cover.
Содержание LT31
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